The sodium salt of fosinopril, (4S)-4-cyclohexyl-1-[[[(RS)-1-hydroxy-2-methylpropoxy](4-phenylbutyl)phosp hinyl]acetyl]-L-proline, propionate (ester) sodium salt, is currently undergoing clinical evaluation as an antihypertensive agent.
Fosinopril, its ability to inhibit the angiotensin converting enzyme and thus lower blood pressure in humans, and formulations of fosinopril including combinations with various diuretics are described by Petrillo, Jr., in U.S. Pat. Nos. 4,337,201 and 4,384,123.